package Collection;

import java.util.ArrayList;
import java.util.Collection;

public class CollectionDemo {
    public static void main(String[] args) {
        /*
        Collection c=new ArrayList();
        c.add("1");
        c.add("2");
        c.add("3");
        c.add("4");
        c.add("5");
        System.out.println(c);
        System.out.println("size:"+c.size());// 输出集合的元素个数
        //isEmpty（）判断集合是否为空集（size（）为0表示空集）
        System.out.println("是否为空集"+c.isEmpty());

        c.clear();//清空集合
        System.out.println("集合已清空");
        System.out.println(c);
        System.out.println("size:"+c.size());
        System.out.println("是否为空集:"+c.isEmpty());

         */
        Collection c=new ArrayList();
        c.add(new Point(1,2));
        c.add(new Point(2,3));
        c.add(new Point(3,4));
        c.add(new Point(4,4));
        c.add(new Point(5,6));
        c.add(new Point(1,2));
        System.out.println(c);
        Point p=new Point(1,2);
        boolean contains= c.contains(p);
        System.out.println("是否包含:"+contains);
        //从当前集合中删除与给定元素o的equals（）比较为true的元素
        //若存在重复元素则只删除一次
        c.remove(p);
        System.out.println(c);


        Collection cc=new ArrayList();
        Point pp=new Point(1,2);
        cc.add(pp);     //将pp添加到cc中----将pp的引用撞到cc中
        System.out.println("pp:"+pp);
        System.out.println("cc:"+cc);

        pp.setX(123);
        System.out.println("pp:"+pp);
        System.out.println("cc:"+cc);
    }
}
